Purr. Whirr.

There is something just so tomorrow about the Russian robo-therapists with their mechanical cats.

Alexander Libin softly strokes the orange-cream fur of NeCoRo -- a semi-realistic cat-robot packed with visual, auditory and movement-sensitive sensors and weighing 3.5 pounds -- while his wife, Elena, serves tea and cookies. They are in their home office on the sixth floor of the Willoughby, a blend-in high-rise in Friendship Heights. In their mid-forties, the Libins are slim-neat and smart-chipper as they talk about the future of pets.

"She's like a real pet," Alex says. He's petting a tabby nicknamed Cleo and, by gosh, it does look like a cat, or some come-alive stuffed animal from a high-end horror movie. It is much more lifelike than Sony's Erector-Set-like robo-dog, Aibo.

Cleo lounges on the dining table, stretches its paws, arches its back, twitches its tail, opens and shuts its eyes. When it turns its neck you can hear a creepy mechanical whirring sound: reh-uh-reh, reh-uh-reh .

Self-described robo-therapists and affiliated faculty members at Georgetown University, the Libins believe in the restorative value of animal companions. The catbot, they explain, is easier for many people -- the elderly, the allergy-stricken, the autistic and disabled children and adults -- to relate to than a real cat. Developed by Omron Corp. of Japan, the mecho-pets are not yet available in the United States, Libin says.

They do not have to be fed or cleaned up after. Other variations -- a teddy bear and a baby seal -- are in development at other labs, and some people believe robotic pets of all kind will be omnipresent in the near future.

Cleo meows obnoxiously and occasionally hisses unless you touch it a certain way, tripping special sensors, and then it closes its eyes, relaxes and purrs or mews contentedly. "She just got back from a conference where she met 50 people," Elena says, talking about the catbot.

"That makes Cleo a little nervous," Alex says.

The whole scene makes you a little nervous. As you delve into the future of pets on this planet, and any others we may land on, you discover at least three possibilities: robotic, cloned and biologically reprogrammed. It's a foggy, uncharted world of cuddly robots, copycat puppies, nonallergenic cats, glowing fish, gargantuan guinea pigs, miniature hippos and the reestablishment of endangered or extinct species that could put us all in danger.

Because pets are not human but are endowed with personality, intelligence and emotion, they are the perfect foils -- in-between beings -- for our scientific curiosity. Think about it. Of course scientists are going to tamper with their genetic structures! You bet they'll tinker with their bloodlines! Breeders have been doing that for years. But now pet researchers can implant software, readjust the genome and conduct experiments in interspecies embryo transfer in ways that have never been done before.

"I'm not scared of the robots," says Alex as he pets Cleo. "I'm scared of the people."

Copies for Life

America is pet crazy. We own more than 140 million pets, according to the Pet Food Institute. Talk to pet industry folks about the future and they send you to Blockbuster to rent "The 6th Day," a 2000 Arnold Schwarzenegger clunker that includes a lengthy contemplation of pet cloning.